Fire-escape



(No Model.)

A; O. ELLITHOBPE;

FIRE ESCAPE.

No. 277,891. 'Paten (1 Ma ,1883.

\A/ i nnes'segz LLVEhtEIr:

' to its first or normal position.

'" UNITED STATES 1 P TENT OFFICE.

ALBERT o. ELLITHORPE, on CHICAGO, ILLINOIS.

FIRE-ESCAPE.

SPECIFICATION forming part of Letters Patent No. 277,891, dated May 22, 1883.

I Application filed February 15, 1883. (No model.)

To all whom it may concern Beit known that I, ALBERT (J. ELLITHORPE of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Fire-Escapes and ldo hereby declare that the following is afull, clear, and exact description of the invention, which will enable others skilled in theart to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

The object of my invention is to provide an easy and perfectly-safe means of exit from burning buildings, which will, after having easily lowered the person tothe ground and is relieved of his weight, automatically return This is accomplished by a device which utilizes atmospheric resistance and vacuum, consisting of an airtight cylinder, in the heads of which a shaft is journaled, and between which the same. is screwthreaded, so that when the shaft re volves by reason of the unwinding of the escape-rope a diaphragm in the cylinder, which is tapped to receive the threaded part of said shaft, will be moved from one end to the other ofsaid cylinder, creating a vacuum on its receding side and compressing the air on its advancing side, thus acting as a brake to the shaft, permitting it to revolve to unwind the escape-rope only as the compressed air on the advancing side of the diaphragm can escape to partially fill the vacuum created on the receding side of the same. When the escape-rope has reached the ground and is relieved of its load the back-pressure of the compressed air on the diaphragm andthe tendency of a weighted rope to unwind will reverse the motion of the shaft, th us opening valves in the diaphragm to equalize the air on either side of the same, and restoring the device to its normal-position. In the drawings, Figure 1 is a vertical longitudinal section, and Fig. 2 is a front elevation.

111 the drawings, A represents ,an air-light .cylinder,in the heads a a of which is journaled the shaft B, passing centrally and longitudi nally through the same.

On one end of the shaft B isplaced a drum, 7 G, ofsuitable diameter, around which is wound the escape-rope b, and on the other end of said shaft is a drum, D, smaller in diameter than drum 0, around which the weighted rope (I is wound in a direction contrary to that of the escape-rope. Thus when the escape-rope is Wound on its drum the weighted rope will be unwound, and vice versa. The shaftB between the heads a a of the cylinder is screw-threaded, and passes through the tapped perforation of the diaphragm E in the cylinder, the periphery ofsaid diaphragm fitting snuglyagainstthe annnlar surfaces of the same. This diaphragm E is prevented from revolving with the shaft by oneormoreguide-rods,e,whichareplacedlongi- 6 tudinally,"and are secured in theheadsofthecylin'der and pass through suitable perforations in said diaphragm, near its periphery. When, therefore, the shaft revolves so as to unwind the escaperope from the drum the diaphragm, 7o

which in its first position will be near the head of the cylinder farthest from the escape-rope, will be moved toward it, rarefying the air on its receding side and compressing the air before it, thus retarding the forward movement of saiddiaphragm according as the compressed air can escape into the vacuum to'increase its expansibility. This action of the air in the cylinder on the diaphragm makes it act as a brake on the shaft, permitting it to revolve So just so fast, or at a safe rate of speed, lowering the person having hold of or attached to the escape-rope carefully to the ground. When the escape-rope is relieved of its load the com pressed air in front of the diaphragm, the rare 8 fied air back of it, and the tendency of the weighted rope (Z to no wind combine to reverse the motion of the shaft and return the dia phragm to its original position. This backward movement of the diaphragm is materially assisted, when it has reached that pointin the cylinder where the consistency of the air on either side of it is about equal, by the opening of one or more valves, 9 g, in the diaphragm, thus avoiding the resistance from atmospheric pressure it mightotherwise experience. When the escape-rope is rewound on the drum the diaphragm will have returned to its first or nor mal position, and the device will be ready for another trip.

To prevent are shaft from moving longitudinallyI place collars on it flush against the boss of the heads of the cylinder; but this .can be accomplished just as well and more economically by placing the drums on either end of the shaft flush against the said bosses.

If desired, and in order to avoid any possibility of a sudden precipitation to the ground when aperson is beiuglowered, I placea spring, G, on the inside of the head (0 nearest the escape-rope drum, of any suitable construction, which acts as a cushion,against which the diaphragm will'bear when the escape-rope has unwound and reached, say, within six feet of the ground. This would avoid the possibility of a sudden shock when striking the ground.

If desired, the weight attached to the end of the roped may be placed in a vertical cylinder its peripheries fitting snugly against the an'nular circumference of said cylinder, so that it will compress the air in the cylinder as it is raised, thus furnishing extra resistance to the revolutions of the shafts as the escape-rope is being unwound. In this event the weight would be provided with valves similar to those in the diaphragm, sothat as the weight is lowered it will experience no opposition from atmospheric pressure, the whole of which is shown in Fig. 1.

I do not consider it beyond the scope of my invention if two diaphragms are used instead of one, in which case the shaft would have a right and alet't screw-thread, commencing from the center of length of the same. The diaphragms would move in opposite directions from the center of length of the cylinder toward the ends of the same when the escaperope was unwinding, and then from the ends to thecenter of thecylinder when said rope was being rewound. When there are two diaphragms acting in the above manner it is obvious the resistance of the vacuum created between the two would be sufficient of itself to accomplish the object of myinventiomand the cylinder-heads may be of open-worl only, adapted to furnish bearings for the shaft.

It will be understood that the pitch of the screw-threaded part of the shaft and the length of the escape-rope will be regulated according to the altitude of the device, or, in other words,

the distance to he traveled to reach the ground.

My invention may be placed above or below the window, or in any suitable position on the outside of a building, and it maybe made more ornamental than reference to the drawings might suggest. It may also be used in commercial houses for lowering goods, being much safer in handling than the ordinary rope and pulley now in common use. i

It will be seen from the above that I do not confine myself to a double-headed cylinder, as, if desired, the machine may be operated either with a vacuum or by atmospheric resistance.

What I claim as new, and desire to secure by Letters Patent, is

1. An automatic and'pneumatic fire-escape consisting of an air-tight cylinder, a shaftrunning centrally and longitudinally through the same, which is screw-threaded within and between the heads thereof, and a non-revolvin g diaphragm within said cylinder, tapped to receive said shaft, which, as the shaft revolves, is moved from one end of the cylinder to the other, creating a vacuum on its receding side and compressing the air before it, thus retarding its too rapid movement .forward and controlling the revolutions of the shaft.

2. The combination ofa shaft passing longitudinall y and centrally through an air-tightcylinder, and screw-threaded between the heads thereof, a weighted rope wound around the end of said shaft, and a diaphragm within said cylinder which moveslongitudinally, and is tapped to receive said shaft, as hereinbel'ore described. v

'3. The combination of the cylinder, the shaft, one or two diaphragms having valves, the escape-rope, and the weighted rope, substantially as set forth.

In testimony that I claim the foregoing as my own I hereunto affiX my signature in presence oftwo witnesses.

' ALBERT O. ELL'ITHORPE.

\Vitnesses JAMES H. OoYNE, F. D. THOMASON. 

